"An error occured" is returned if user tries to open iTwin in which they do not have sufficient iModelHub permissions

[aleksas-lukauskas]

Make sure a user does not have any iModelHub permissions on some iTwin in which they have other permissions.
Try accessing such iTwin in My iTwins page, like:
https://qa-developer.bentley.com/my-itwins/28121271-dbf4-46ea-9666-1a8f80be4bc4/imodels/
Response:

The error message is not clear for a user. The error message should be more clear, like it is on CONNECT portal: